The present invention relates to a motorcycle having a front wheel suspension with a forked wheel support connected by at least one trailing link to the motorcycle frame.
The motorcycle “K 1200 S” from BMW has a front wheel suspension which is known under the name “Duolever.” Viewed kinematically, the Duolever front wheel suspension is a jointed rectangle, which is formed by two trailing links situated one above another and each mounted so it is pivotable on the frame or on an engine housing. The front ends of the trailing links are each connected via a ball-and-socket joint to a forked wheel support, which is produced in the K 1200 S in one piece from aluminum chill casting. The springing and damping is assumed by a suspension strut, which is linked to the lower of the two trailing links and is supported against the frame. A trapezoidal scissors joint mounted on the “control head” and wheel support is coupled to the control arm and transmits the steering movements input via the handlebars to the wheel support.
The object of the invention is to provide a motorcycle having a front wheel suspension, in particular a “Duolever front wheel suspension” or a “Telelever front wheel suspension,” which offers still better driving comfort in particular in regard to “impact forces” introduced into the wheel support via the front wheel as occur when driving over obstacles, for example.
The starting point of the invention is a motorcycle having a front wheel suspension, in particular a “Duolever front wheel suspension.” Although the invention is predominately described in the following on the basis of a Duolever front wheel suspension, it is to be expressly noted that the invention is also applicable in the so-called Telelever front wheel suspension which has been known for some time from BMW motorcycles, which is distinguished by a telescoping fork, whose lower fork tubes are supported in an articulated manner via a trailing link on the frame or the engine housing of the motorcycle.
A Duolever front wheel suspension has a forked wheel support having two rigid fork arms, on which a front wheel of the motorcycle is mounted. The wheel support may be an aluminum cast part, for example. The wheel support is suspended on the motorcycle using two pivotable trailing links situated one above another. The rear ends of the trailing links may be connected via pivot joints, for example, to the frame and/or to the engine housing of the motorcycle. The trailing links are provided for absorbing forces introduced via the front wheel into the wheel support and allow the wheel support to spring in and out. Each of the two trailing links may have two arms whose rear ends are pivotably connected on the left or right side of the motorcycle to the motorcycle frame or to the engine housing. The two arms of each of the two trailing links run together toward the front and are each connected there via a ball-and-socket joint to the wheel support.
In the case of a Duolever front wheel suspension, the core of the invention is that at least one of the two joints is elastically connected to the assigned trailing link and/or to the wheel support. In this context, the term “elastically” means that impacts introduced primarily in the travel direction via the front wheel into the wheel support, e.g., when driving over obstacles, may be “cushioned” to a certain extent, i.e., not introduced completely unsprung from the wheel support via the joints into the trailing links and further into the motorcycle frame and/or the engine housing.
Accordingly, in the case of a Telelever front wheel suspension, the core of the invention is that the ball-and-socket joint via which the trailing link—the single one provided here—is connected to the fork bridge connecting the lower of the fork tubes of the telescopic fork, is elastically connected to the trailing link and/or to the assigned fork bridge. A motorcycle having “Telelever front wheel suspension” according to the invention thus has at least the following features:                a telescopic fork having two upper fork tubes and two lower fork tubes displaceable in relation thereto,        a fork bridge which connects the two lower fork tubes to one another,        a trailing link having a front end viewed in the travel direction which is connected via a joint (20) to the fork bridge, the joint being connected elastically to the trailing link and/or to the fork bridge.        
It is to be expressly noted that all of the features or feature combinations described in the following which relate to the elastic attachment of the ball-and-socket joint(s) in the Duolever to the assigned trailing links and/or to the wheel support may also be applicable in a constructively identical way to the elastic attachment of the ball-and-socket joint of a Telelever front wheel suspension, in which, as described above, the fork bridge connecting the lower fork tubes is connected via a ball-and-socket joint to a trailing link, which is in turn connected in an articulated manner to the frame and/or to the engine housing of the motorcycle.
In a Duolever front wheel suspension, at least the joint via which the upper trailing link is connected to the wheel support is preferably elastically “attached.” As already noted, a component connection which is elastically formed appropriately in the longitudinal direction of the motorcycle may alternately be provided between the joint(s) and the wheel support and/or between the joint(s) and the particular assigned trailing link.
A longitudinal elasticity of this type may be achieved using a spring plate, for example. Elastomer elements may be used alternatively or additionally thereto.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.